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TOPIC: Condensation Issues

Unfinished attic w/ partial metal roof has drips; want to finish attic

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Hello: Thank you for taking the time to look over and answer my question. We recently purchased a home. It was built in the early 1900's. It has a basement, a first and second floor, and an attic. The attic is unfinished. We would like to finish it so that we can add a guest room and a half bath, plus a storage room. The house has two different roofing materials: Shingles cover 2/3 of the roof; metal covers 1/3 of the roof (if you look down at the roof from the sky, it would look like a "T" turned sideways. If you stand facing the front of the home, half of the left side of the roof is metal; the other half, along with the front and back sides of the roof are shingled) We don't have any dripping issues with the shingled part of the roof; it's the metal part that "sweats". When one goes into the attic and looks at the metal roof, one comes to the realization that there is nothing between you and the great outdoors except for that sheet of metal. Short of tearing off the metal roof and installing shingles instead (which we are loathed to do because our roof has such a steep angle to it) how can we go about taking care of this condensation issue so that we can confidently move on to finishing up this space? Thanks a million.
Guest User

1/13/2010
Condensation occurs when warm moist air hits a cool surface. Ways to avoid it include insulation, ventilation, and moisture control. Going to www.airvent.com may be helpful for your research. Todd Miller
Todd Miller
Isaiah Industries, Inc.

1/15/2010
Simple really, metal roof on a residential house is always gonna cause problems. You have already said the right answer--which part of the roof is not 'sweating'. Pay the money and do the right job.
Guest User

1/22/2010
A metal roof is one of the most cost effective things you can do for your house. Like any other roofing material, you have to make sure it is installed properly. If you are going to have an enclosed attic with insulation on the attic floor, install soffit and ridge vents to ventilate the attic. The other option would be to insulate the bottom of the roof and have a vapor barrier on the bottom of the insualtion. Alternatively, you could use urethane spray insuation.
Ken Buchinger
NCI Building Systems, Inc.

1/22/2010
I want to try to help as well. Forget about the types of roof for a minute. The real problem is warm moist air is leaking into your attic. If you want to throw money at a problem throw it at that problem. The air you are paying for through you heating bills is leaking into your attic. In the winter time, with proper intake and exhaust ventilation your attic temperature should be pretty close to within 10 degrees of outside temperature. I would check that you have the proper insulation, then adequate intake and exhaust ventilation throughout entire attic area. This can be done correctly when you finish your attic. Make sure whoever does this doesn't cheat in this area. You must maintain the ventilation space below the metal or shingles, and fur the rafters out so you can install adequate insulation for your area. As far as shingles vs. metal, It is possible that the metal roof is the original roof. The shingles are definitely not, and you will be doing the shingled 2/3's again soon enough.
Guest User

1/22/2010